1. Field of the Invention
The present invention relates to packet-switched telephony. Specifically, the present invention relates to full-duplex audio communication using a half-duplex audio circuit.
2. Description of Related Art
It is now common to transmit voice signals over data networks such as the Internet which is essentially a collection of packet switched networks. The processing of voice signals for transmission is usually performed by audio cards in a personal computer (PC) platform.
There are two types of audio cards that are designed to support two types of audio communication over such data networks: half-duplex and full-duplex. In half-duplex communication, voice data can be transmitted in only one direction at a time. The speaker is required to press a xe2x80x9cpush-to-talkxe2x80x9d or xe2x80x9crequest-to-talkxe2x80x9d every time he or she wants to transmit his or her voice data. Examples of audio half-duplex communication include the walkie-talkie transmission. In contrast, full-duplex communication allows voice data to be transmitted in both directions simultaneously. An example of full-duplex communication is the conversation over the regular telephone line. Speakers on both sides freely speak. Audio cards implementing the half-duplex protocol have simple hardware circuitry but do not provide the desirable normal conversations as in full-duplex communication.
Accordingly, there is a need in the technology to provide full-duplex mode in half-duplex audio card with smooth transitions from one state to another without causing too many audio artifacts.
The present invention discloses a method for providing full-duplex audio communication utilizing a half-duplex audio circuit in an audio communication system. The method comprises the steps of: (1) configuring an idle state, a listen state, and a talk state; (2) receiving an event triggered by one of an incoming speech, an outgoing speech, and a talk request from the half-duplex audio circuit; and (3) transitioning from one of the states to any one of the states in response to the event to provide full duplex communication.